In order to obtain an improvement in welding components to a printed circuit, especially for transverse components welded at both faces of a printed circuit, welding materials having different characteristics are used in each end of the components in such a way that one weld is not qualitatively affected by the other weld. More specifically, this invention is a method that includes using welding alloys of different melting points for each face of the component in order to avoid re-melting during the second welding which is typically made with the alloy tin/lead having a melting point of 183.degree. C.
The present invention consists of improvements in the manufacturing processes of service boxes and their parts whose novel characteristics in manufacturing, shaping and design fulfill the role for which had been specifically designed with a maximum safety and efficiency.
In Spanish Patent No. 9 302 193 to the same Applicant, improvements in the manufacturing processes of service boxes and their parts was disclosed which relate to Spanish Patent No. 9 200 325 which disclosed improvements in the manufacturing processes of service boxes and their parts. These improvements consist of the use of special alloys in the welding operations of the type corresponding to the formula 95 Sn, 5 Sb, and 52 Sn, 45 Pb, 3 Sb, as well as to the application of a new substrate material formed with glass fibers in the outside surface and epoxy-paper on the inside surface, and finally a varnish or coating of a photo-sensitive bath, a water repellent, and corrosion resistant liquid.
The practice in the application of these improvements has introduced new technical factors and have led to the discovery of a little known phenomenon, which had as a consequence, the creation of a novel technical solution and an improvement in the manufacturing technologies of service boxes and their parts, in which welding procedures are a very important part of same.
The role of the welding is capital since it insures the electrical union between two conductive materials thus avoiding high tension falls and keeping the electrical unions stable.
Mechanically speaking, the welding also has a role since it must support the components in order to guarantee the passage of power. That mechanical union must be resistant to vibration., temperature changes, humidity, corrosion and other environmental factors.
Currently, the welding made by a wave bath using an alloy of tin-lead has the following characteristics: melting point 183.degree. C., eutectic T1=TS, and electrical conductivity 11.50% of copper.
In order to obtain an improvement in the welding, especially of transverse components welded at both faces of a printed circuit, welding processes of different characteristics are needed in each end of the components, in order that each welding is not qualitatively affected by the other.